Mining Pump

Abstract

To provide a mining pump that is less affected by a slurry component.SOLUTION: A mining pump comprises a production pipe, a pump rotor, and a pump stator surrounding the pump rotor. The pump rotor has a pump shaft, and an impeller rotating with the pump shaft. The pump stator has a stator body forming a flow path outside the impeller, a stator shroud, and a plurality of vanes connecting the stator body and the stator shroud. The stator shroud has a guide surface formed on an extension line in an outflow direction of the flow outflowing from the vanes, and a step surface connected to an upper edge of the guide surface and extending in a direction intersecting the guide surface.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to mining pumps. [Background technology]

[0002] As a device for pumping crude oil from an oil well, a pump called an ESP (Electrical Submersible Pump) has been widely used. As shown in the following Patent Document 1, this type of pump includes a rotating shaft that rotates around a rotating axis, a plurality of impellers that are integrally provided on the rotating shaft, and a casing that covers the rotating shaft and the impellers from the outer periphery. This pump is placed in a pipe inserted into a well (oil field), and pumps underground oil upward by rotating the rotating shaft with an electric motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2018-508701 Summary of the Invention [Problem to be solved by the invention]

[0004] It is known that the crude oil extracted contains a large amount of slurry components, which are fine solid particles, in addition to liquid components. If such slurry components get mixed into the bearings of the rotating shaft or the surface of the rotating shaft, wear and tear may progress, and the pump may not be able to perform normally.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a mining pump that is less affected by slurry components. [Means for solving the problem]

[0006] In order to solve the above problems,The mining pump according to the present disclosure comprises a cylindrical production pipe along an axis extending in the vertical direction, a pump rotor extending in the axial direction within the production pipe, and a pump stator surrounding the pump rotor between the production pipe and the pump rotor. The pump rotor has a plurality of pump shafts connected in sequence in the axial direction, and an impeller having a plurality of stages provided on each of the pump shafts and rotating together with the pump shaft to pump crude oil upward. The pump stator has a stator body that is cylindrical extending along the axis and forms a flow path on the outside of the impeller, a stator shroud that faces the impeller from above in the axial direction and forms the flow path, and a plurality of vanes that connect the stator body and the stator shroud and are arranged at intervals in the circumferential direction. The stator shroud has a guide surface formed on an extension of the outflow direction of the flow flowing out of the vane, and a step surface connected to the upper edge of the guide surface in the axial direction and extending in a direction intersecting the guide surface, and the step surface extends downward in the axial direction as it moves radially inward. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a mining pump that is less affected by slurry components. [Brief description of the drawings]

[0008] [Figure 1] A vertical cross-sectional view showing the configuration of a mining pump according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of a main portion of a mining pump according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is an illustrative diagram showing fluid flow during operation of a mining pump according to an embodiment of the present disclosure. [Figure 4] An enlarged cross-sectional view of a main portion showing a modified example of a mining pump according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Mining pump configuration) Hereinafter, a mining pump according to an embodiment of the present disclosure will be described with reference to Figs. 1 to 3. The mining pump 100 according to this embodiment is a device for pumping crude oil from an oil well. As shown in Figs. 1 and 2, the mining pump 100 includes a pump body 90, a motor 80, a drilling pipe 9, and a lower end thrust bearing 10. The pump body 90 is driven by power supplied from the motor 80. The drilling pipe 9 covers the pump body 90, the motor 80, and the lower end thrust bearing 10 from the outer periphery side, and has a cylindrical shape centered on an axis O extending in the vertical direction.

[0010] The pump body 90 has a production pipe body 1a, a pump rotor 21, and a pump stator 3. The production pipe body 1a is a cylindrical member that is coaxial with the drilling pipe 9 and is disposed on the inner periphery side of the drilling pipe 9. The pump rotor 21 has a plurality of pump shafts 21s connected in the direction of the axis O, a coupling sleeve (not shown) that connects the pump shafts 21s to each other, and a plurality of impellers 5 fixed to these pump shafts 21s. The configuration of the impeller 5 will be described later.

[0011] The pump stator 3 has a stator body 3h that covers the impeller 5 from the outer periphery side, and a stator extension 3e. The stator body 3h repeatedly expands and contracts in diameter from bottom to top to accommodate the impeller 5 and define a stator flow path Fs through which crude oil flows. The configurations of the impeller 5 and the pump stator 3 will be described later. The stator extension 3e is integrally provided below the stator body 3h and has a cylindrical shape centered on the axis O. A lower end thrust pad 7d is attached to the lower end of the stator extension 3e.

[0012] The motor 80 has a production pipe tip 1b, a motor rotor 22, a coil 81, and a magnetic member 22m. The production pipe tip 1b is cylindrical and integrally provided below the above-mentioned production pipe main body 1a. The production pipe main body 1a and the production pipe tip 1b together form the production pipe 1. A plurality of coils 81 arranged in the circumferential direction are provided on the inner peripheral surface of the production pipe tip 1b. The coils 81 generate electromagnetic force by current supplied from the outside. The motor rotor 22 is disposed on the inner peripheral side of the coils 81 and has a cylindrical shape extending along the axis O. The motor rotor 22 is connected to the pump shaft 21s located at the lowest position among the plurality of pump shafts 21s that form the above-mentioned pump rotor 21 via a lower end spline coupling 30d. The plurality of pump shafts 21s and the motor rotor 22 together form the rotor 2. A permanent magnet is provided on the outer peripheral surface of the motor rotor 22 as a magnetic member 22m. A rotational force is applied to the rotor 2 by an electromagnetic force generated between a magnetic field generated by energizing the coil 81 and the magnetic field of the magnetic member 22m.

[0013] The production pipe tip 1b is supported from below by an annular support part 4 that protrudes radially inward from the inner circumferential surface of the drilling pipe 9. The opening on the inner circumferential side of the support part 4 is an opening H for taking in crude oil. The lower end of the motor rotor 22 is inserted into this opening H. In addition to the opening H, a suction passage F for sucking in crude oil is formed inside the motor rotor 22. This suction passage F is connected to a stator passage Fs formed on the inner circumferential side of the pump stator 3.

[0014] Furthermore, an annular lower end thrust collar 6d is provided on the outer circumferential surface of the motor rotor 22 above the magnetic member 22m, protruding radially outward and centered on the axis O. The lower end thrust collar 6d is supported from above and below by lower end thrust pads 7d provided on the inner circumferential surface of the pump stator 3 (stator extension 3e). The lower end thrust collar 6d and the lower end thrust pads 7d form a lower end thrust bearing 10. The rotor 2 (pump rotor 21 and motor rotor 22) is supported rotatably about the axis O relative to the pump stator 3 by the lower end thrust bearing 10 and an intermediate thrust bearing Bs, which will be described later.

[0015] Next, the configuration of the impeller 5 will be described with reference to Fig. 2. The impeller 5 has a disk 51, blades 52, and a shroud cover 53. The disk 51 is fixed to the outer circumferential surface of the pump shaft 21s and has a disk shape centered on the axis O. The downward surface of the disk 51 is a disk main surface 51m. The disk main surface 51m is curved from the radial inner side to the radial outer side as it moves from the bottom to the top.

[0016] A plurality of blades 52 are provided on the disk main surface 51m and arranged at intervals in the circumferential direction. Although not shown in detail, each blade 52 is curved from the inside to the outside in the radial direction toward the front side in the rotation direction of the rotor 2. Also, the blade height (the rise dimension from the disk main surface 51m) of the blade 52 gradually decreases from the bottom to the top.

[0017] The shroud cover 53 is funnel-shaped and covers from below the plurality of blades 52. The shroud cover 53 is curved from the inside to the outside in the radial direction as it goes from the bottom to the top.

[0018] The impeller 5 configured as above is covered by the stator body 3h from the outer circumferential side. Of the inner circumferential surface of the stator body 3h, the surface facing the shroud cover 53 is defined as the facing surface 31. Of the inner circumferential surface of the stator body 3h, the region adjacent to the upper side of the facing surface 31 is defined as the connection surface 32. The connection surface 32 is curvedly recessed toward the radially outer side. Furthermore, the region adjacent to the upper side of the connection surface 32 is defined as the downstream surface 33. The downstream surface 33 extends from the radially outer side toward the radially inner side as it goes from the lower side to the upper side. The downstream surface 33 is provided with a plurality of vanes 60 and a stator shroud 3s fixed to the inner circumferential side of the vanes 60. Each vane 60 is in the form of a plate protruding radially inward from the downstream surface 33. A plurality of vanes 60 are arranged at intervals in the circumferential direction. The stator shroud 3s faces the above-mentioned disk 51 from above.

[0019] The outer peripheral surface of the stator shroud 3s is composed of a guide surface 34, a cylindrical surface 35, and a step surface 36. The guide surface 34 extends from the outside to the inside in the radial direction as it moves upward from the lower end side of the stator shroud 3s. The guide surface 34 is curved so as to be concave toward the inside in the radial direction. As shown by the arrow in FIG. 2, the guide surface 34 is located on an extension line of the outflow direction of the flow flowing out from the vane 60. In other words, all straight lines normal to the rear edge of the vane 60 extend toward this guide surface 34. The cylindrical surface 35 is connected to the upper side of the guide surface 34. The cylindrical surface 35 extends parallel to the axis O. The step surface 36 is connected to the upper edge of the cylindrical surface 35. The step surface 36 spreads in the radial direction, which is a direction intersecting the guide surface 34 and the cylindrical surface 35. The cylindrical surface 35 and the step surface 36 form a rectangular step in cross section. The radially inner edge of the step surface 36 faces the outer circumferential surface of the pump shaft 21s.

[0020] (Action and effect) Next, the operation of the above-mentioned drilling pump 100 will be described. To operate the drilling pump 100, first, the rotor 2 is rotated by supplying power to the above-mentioned motor 80. When the rotor 2 rotates, crude oil in the oil well is sucked upward by the pump body 90 from the opening H formed at the lower end of the drilling pipe 9. At this time, the crude oil is also sucked up by the suction flow passage F formed in the motor rotor 22.

[0021] It is known that the extracted crude oil contains a large amount of slurry components, which are fine solid particles, in addition to liquid components. If such slurry components get mixed into the bearings or the surface of the pump shaft 21s, wear and tear may progress, and normal pump performance may not be obtained.

[0022] Therefore, in this embodiment, as described above, the guide surface 34, the cylindrical surface 35, and the step surface 36 are formed on the outer peripheral surface of the stator shroud 3s. As shown in FIG. 3, the main stream F1 of crude oil containing a slurry component that flows along the guide surface 34 is given a component in the axial direction by the cylindrical surface 35, and then passes through the step surface 36. Due to the formation of this step surface 36, the main stream F1 is separated. Due to this separation, a separated vortex flow F2 is formed above the step surface 36. Since the separated vortex flow F2 remains, the main stream F1 is less likely to flow into a region radially inward of the guide surface 34 and the cylindrical surface 35. As a result, the possibility that the slurry component will flow toward the outer peripheral surface of the pump shaft 21s is reduced.

[0023] Furthermore, the guide surface 34 is curved so as to extend gradually toward the axis O as it moves radially inward. According to this configuration, the guide surface 34 can smoothly guide the flow of fluid toward the axis O.

[0024] The above-described configuration further includes a cylindrical surface 35 that is formed between the guide surface 34 and the step surface 36 and extends in the direction of the axis O. With this configuration, the cylindrical surface 35 can impart a larger component in the direction of the axis O to the fluid flow direction. As a result, the possibility that the slurry components contained in the above-described main flow F1 will move radially inward can be further reduced.

[0025] In addition, in the above configuration, the step surface 36 extends in the radial direction. With this configuration, the step surface 36 extends in the radial direction, so that the separated vortex flow F2 can be more stably formed in the flow flowing out from the guide surface 34. The more the separated vortex flow F2 develops, the less likely the main flow F1 will move radially inward. As a result, the mining pump 100 can be operated more stably.

[0026] The above describes the embodiment of the present disclosure. Various changes and modifications can be made to the above configuration without departing from the gist of the present disclosure. For example, the above embodiment describes the mining pump 100 as an example. However, the above-mentioned guide surface 34, cylindrical surface 35, and step surface 36 can be suitably applied to any rotary machine that handles a fluid containing solid components such as slurry.

[0027] Furthermore, unlike the above embodiment, it is also possible to form the step surface 36 directly on the upper edge of the guide surface 34 without forming the cylindrical surface 35. With such a configuration, the same effects as those described above can be obtained.

[0028] 4, it is also possible to configure the step surface 36b so that it extends downward in the direction of the axis O as it moves radially inward. With such a configuration, a vortex flow can be more actively and stably formed in the flow flowing out from the guide surface 34 and the cylindrical surface 35.

[0029] <Additional Notes> The mining pump 100 described in each embodiment can be understood, for example, as follows.

[0030] (1) The mining pump 100 according to the first embodiment includes a cylindrical production pipe 1 extending along an axis O extending in the vertical direction, a pump rotor 21 extending in the direction of the axis O within the production pipe 1, and a pump stator 3 surrounding the pump rotor 21 between the production pipe 1 and the pump rotor 21. The pump rotor 21 has a plurality of pump shafts 21s connected in sequence in the direction of the axis O, and impellers 5 each having a plurality of stages provided on each of the pump shafts 21s, which rotate together with the pump shafts 21s to pump crude oil upward. The pump stator 3 extends along the axis O. The stator shroud 3s has a stator body 3h having a cylindrical shape extending in the direction of the axis O to form a flow passage on the outside of the impeller 5, a stator shroud 3s facing the impeller 5 from above in the direction of the axis O to form the flow passage, and a plurality of vanes 60 connecting the stator body 3h and the stator shroud 3s and arranged at intervals in the circumferential direction, the stator shroud 3s having a guide surface 34 formed on an extension of the outflow direction of the flow flowing out from the vanes 60, and a step surface 36 connected to an upper edge of the guide surface 34 in the direction of the axis O and extending in a direction intersecting the guide surface 34.

[0031] According to the above configuration, the flow of the fluid flowing out of the vane flows upward along the guide surface 34. Thereafter, when the flow passes through the step surface 36, the step surface 36 causes the flow to separate, forming a vortex above the step surface 36. The formation of this vortex makes it difficult for the main flow of the fluid to enter the area directly above the step surface 36. In other words, it becomes difficult for slurry components to enter this area. As a result, it is possible to reduce the possibility that slurry components will get mixed into the surface of the pump shaft 21s located on the inner circumferential side of the stator shroud 3s.

[0032] (2) In the mining pump 100 according to the second embodiment, the guide surface 34 is curved so as to extend gradually in the direction of the axis O as it moves radially inward.

[0033] According to the above configuration, the guide surface 34 can smoothly guide the flow of fluid in the direction of the axis O.

[0034] (3) The mining pump 100 of the third embodiment further has a cylindrical surface 35 formed between the guide surface 34 and the step surface 36 and extending in the direction of the axis O.

[0035] According to the above-mentioned configuration, the cylindrical surface 35 can impart a larger component in the direction of the axis O to the fluid flow direction.

[0036] (4) In the mining pump 100 according to the fourth aspect, the step surface 36 extends radially.

[0037] According to the above-described configuration, the step surface 36 extends in the radial direction, so that a vortex can be formed in the flow flowing out from the guide surface 34 more stably.

[0038] (5) In the mining pump 100 according to the fifth aspect, the step surface 36 extends downward in the direction of the axis O as it moves radially inward.

[0039] According to the above configuration, the step surface 36 extends downward in the direction of the axis O as it moves radially inward, so that a vortex can be formed more actively and stably in the flow flowing out from the guide surface 34. [Explanation of symbols]

[0040] 100 Mining Pump 1 Production Management 1a Production pipe body 1b Production pipe tip 2 Rotors 3 Pump stator 3e Stator extension 3h Stator body 4 Support part 5 Impeller 6d Lower Thrust Collar 7d Lower end thrust pad 9. Drilling Pipe 10 Lower end thrust bearing 21 Pump rotor 21s pump shaft 22m Magnetic material 30d Lower Spline Coupling 31 Opposite Surface 32 Connection Surface 33 Downstream side 34 Guide Surface 35 Cylindrical Surface 36,36b Step surface 51 Disc 51m disk main surface 52 Blade 53 Shroud cover 60 Vane 80 Motor 81 Coil 90 Pump body F Suction passage F1 mainstream F2 Vortex flow O axis

Claims

1. A cylindrical production pipe having an axis extending in the vertical direction; a pump rotor extending in the axial direction within the production pipe; a pump stator surrounding the pump rotor between the production pipe and the pump rotor; Equipped with The pump rotor is A plurality of pump shafts connected in sequence in the axial direction; Each of the pump shafts has a plurality of stages, and an impeller rotates together with the pump shaft to pump the crude oil upward; having The pump stator includes: a stator body having a cylindrical shape extending along the axis to form a flow passage on the outside of the impeller; a stator shroud that faces the impeller from above in the axial direction to form the flow path; a plurality of vanes connecting the stator body and the stator shroud and arranged at intervals in a circumferential direction; having The stator shroud includes: A guide surface is formed on an extension line of the outflow direction of the flow outflowing from the vane; a step surface connected to an upper edge of the guide surface in the axial direction and extending in a direction intersecting the guide surface; having A mining pump in which the step surface extends radially inward and then downward in the axial direction.

2. 2. The mining pump of claim 1, further comprising a cylindrical surface formed between the guide surface and the step surface and extending in the axial direction.

3. The mining pump according to claim 1 or 2, wherein the guide surface is curved so as to extend gradually in the axial direction as it moves radially inward.

4. A mining pump as claimed in any one of claims 1 to 3, wherein the step surface extends radially.

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